I came across this article on Yahoo News this morning. Sounds like my 3 cup a day habit might just serve me well:

..Research shows that heavy coffee drinkers have a lower risk of developing Type 2 diabetes, and now scientists in China may have discovered why.

Prior studies have shown that people who drink four or more cups of coffee a day have a 50 percent lower risk of Type 2 diabetes, and that every extra cup of coffee brings another decrease in risk of almost seven percent.

Researchers from Huazhong University of Science and Technology, Wuhan University, and Wuhan Institute of Biotechnology in China have cited the protective benefits of compounds in coffee that inhibit a substance called human islet amyloid polypeptide (hIAPP), which has been linked to diabetes, stated science and health news website Science Daily last week in a report on the new study. The study appears in the latest issue of the Journal of Agricultural & Food Chemisty.

Last year, a Harvard University study in the US found that drinking coffee, either decaf or regular, can ward off the risk of deadly prostate cancer. Another recent study found that women who drank five or more cups of coffee a day were 57 percent less likely to develop estrogen receptor-negative breast cancer.

More good news for coffee lovers? Coffee has also been shown to improve brain function in mice studies, with researchers probing the possibility of using coffee as a treatment for people with Alzheimer's disease.

Still health experts don't recommend too much coffee. The US-based Mayo Clinic suggests no more than two to four cups a day, since more than that can cause insomnia, upset stomach, and anxiety.